Flotation process



l slag.

Patented Oct. 12, 1943 N Drawing. Application February 2, 1942,

' Serial No. 429,278

6 claim. (01. 209-186) This invention relates to the concentration by the fioation process of metals, and certain of their compounds occurring in rocks, slags, industrial suspensions and dust. relates more particularly to :a novel flotation agent especially suitable for use in the flotation The invention process for concentrating heavy metallics such as copper, silver, gold, lead and'zinc.

Heretofore, it has been the practice to use sulfurized oils, such as sulfurized pine oil, as sulfidizing and mild collecting agents in the flotation process. At the present time it is common practice to employ'water soluble organic sulfide compounds such as xanthates and dithiophosphates which serve to sulfidize the ore particles as well as to collect them. None of these sulfur bearing agents are particularly effective in obtaining complete recovery of coarse metallic particles such as those which occur by reason of being malleable and which are, therefore, not subject to being finely divided by grinding. The sulfurized oils assist collecting primarily as sulfidizing agents, and at best, when used alone, or with other collectors, are poor collectors as Judged by present day standards. The soluble organic sulfides are more adaptable for collecting coarse ore particles if made from higher alcohols such as amyl alcohol, but, in general, they produce concentrates badly contaminated with gangue so that the ratio of concentration is poor.

An object of the present invention is, therefore, an improved flotation agent which will give a high yield and a high ratio .of concentration of metals from ores and slag.

Another object of the invention is an improved flotation agent which isadapted to recover relatively large metal particles.

Still another object is an improved flotation process'for recovering-metals from ore, slag and the like.

A further object is a flotation process for the recovery of metallic copper, silver and gold from in accordance with my invention these and oils than can be obtained by employing the socalled soluble sulfide collectors, or by other sulfur bearing organic substances now employed 'in flotation processes.

agent.

I: desired, 1 may employ the sulfurized whale oil with other flotation agents, particularly frothing agents heretofore known such as pine oil, pine tars; hard wood creosote oils, coal tar oils, organic detergents such as Duponal and "Tergitol or the ketones and esters of higher alcohols.

I prefer toemploy 0.40 lb. to 2 lbs. of my novel flotation agent per ton of slag or the like; However, metal recovery can be obtainedover-,a

range of 1/l0 to 10 pounds or more of the su1- furized sperm oil per ton of slag.

A s will be understood by those skilled in the art, the process of the invention is carried on by subdividing the ore, slag or other metal containing substances as by grinding and ball milling.

ticls is then removed. from the flotation cell. In

large scale commercial operations this process may be continuous.

It will be understood that sulfurized sperm on is entirely difierent in chemical compositionfrom any organic sulfur containing flotation agent heretofore employed. Sperm oil is found in the head cavities and blubber of the cachelot -or sperm whale'iPhyseter macrocephalus).

While sperm oilis frequentlytermed a fatty oil,.

7 it is not like ordinary fatty oils which are triother objects are attained by employing in o notation process, as a flotation agent, a sulfurized whale oil such as liquid sulfuriaed oils from the sperm oil group including sperm oil and bottlenose oil. The sulfurized sperm oil operates as a collector with frothing properties.

I have found a higher recovery of metallic particles and a higher ratio of concentration can be obtained by employing these sulfurized whale esters of glycerine. Sperm oil is compoad chiefly of the fatty esters of monohydric alcohols of relatively high molecular weight, it being really liquid waxes of the ester type. Commer:

cial sperm oils are thin yeuow liquids and the better qualities are nearly free from odor.

Bottlenose oils may be employed in place of sperm oil, if desired. They are obtained from toothed cetaceouaparticularly the bottlenose Metal particles as large as; 14 mesh can be recovered by this novel flotation whale (Hyperoodon rostratum); the characteristics of this type of oil are much like sperm oil and the commercial oil is known as arctic sperm oil.

As previously stated sperm oil is a mixture of certain esters. The esters are esters of monohydric alcohol with fatty acids of the oleic series, such esters having the following general formula wherein R represents an aliphatic chain of relatively high molecular weight; the acid component being likewise of high molecular weight. It appears from the literature that the principal and characteristic components of sperm oil and similar oils of the sperm oil group are monoesters which are unsaturated or contain double bonds, on each side of the ester group. That is they are esters of oleic acid or homologous acids of the oleic type wit monohydric alcohols of the ethylene series (the series of alcohols corresponding to the oleic series of acids).

The class of mono-esters may be represented by the formula wherein n is at least 1.

Such esters, when sulfurized, form neutral organic sulfur compounds which may be advantageously employed in flotation processes.

By sulfurization the added sulfur saturates the double bonds of the esters yielding products such as presented by the following formula:

The ratio of concentration is determined by dividing the weight of the heads or feed into the weight of the concentrate recovered by the flotation collector i. e.

Weight of concentrate Ratio of concentration 0th 1 (feed) Example 2 A 2000 gram sample of lead zinc ore from southwestern Wisconsin was ground in a ball mlllto 85% minus 200 mesh and treated in a Patek flotation cell to produce a lead concentrate,

where n is at least 1.

The reaction to form the sulfurized sperm oil may be conducted at temperatures of 300-385 F. Sulfur in the form of flowers of sulfur or sulfur flour may be advantageously employed. The amounts of sperm oil and sulfur in the reaction may vary for example, a ratio of sulfur to oil between 5:95 and 2:80 has been found satisfactory. Methods of forming these sulfurized whale oils are further described in U. S. Patent 2,179,060. The sulfurized sperm oils may be purchased on the market from several sources.

As stated above the use of sulfurized sperm oil as a flotation collecting agent is capable of producing richer concentrates and better recovery than are obtainable with the well known soluble organic sulfur bearing flotation agents.

These important features of the invention. will be more fully understood by reference to the following examples.

Example 1 When a similar amount of the'same material a zincconcentrate and a tailing consisting of pyrite and gangue. The feed contained 1.23% lead and 7.86% zinc. A lead concentrate was formed after five minutes flotation with the following agents:

' Lbs/ton sulfurized sperm oil 0.40 Sodium cyanide 0.15 Lime. 3.0

sulfurized sperm oil Copper sulfate The zinc concentrate contained 59.2% zinc and the zinc recovery was 94%.

Example 3 A 2000 gram sample of amygdaloid copper ore from the Lake Superior district was treated in a laboratory flotation cell after having been ground to minus 48 mesh. The feed contained 18 pounds of copper perton and the tailing 1.4 pounds of copper per ton. After cleaning, the concentrate contained 82% copper. The reagents employed were 0.6 pound oi sulfurized sperm oil as a collecting agent and 0.2 pounds of methyl amyl ketone as frother.

What I claim is:

1. The method of effecting concentration of relatively coarse metal containing ore particles of a size of the order of 14 mesh by the flotation process which comprises adding to a mineral pulp a sulfurized sperm oil, and subjecting the resulting mixture to a flotation operation.

2. The method of effecting concentration of relatively coarse metallic particles of a size of the order of 14 mesh by flotation which comprises agitating and aerating a metal containing pulp with a sulfurized sperm oil.

' 3. The method of effecting concentration of metallic particles including relatively coarse metailic particles of a size of theorder of 14 mesh by flotation which comprises agitating and aerating a metal containing pulp with a sulfurized sperm oil.

4. The method of effecting concentration of metallic particles occurring in slag, including relatively coarse metallic particles of a size of the order of 14 mesh by. flotation, which comprises comminuting the slag, forming a pulp 6. The method of eflectingconcentration of relatively coarse silver particles of a size of the order of 14 mesh by flotation which comprises agitating and aerating a silver containing pulp 5 with a sulfurized sperm oil.

JOl-lN MQPATEK. 

